docs: def destroy_cloudwatch_event(app='', env='dev', region=''):
      """Destroy Cloudwatch event subscription.
  
      Args:
          app (str): Spinnaker Application name.
          env (str): Deployment environment.
          region (str): AWS region.
      Returns:
          bool: True upon successful completion.
      """
  
      session = boto3.Session(profile_name=env, region_name=region)
      cloudwatch_client = session.client('events')
  
      event_rules = get_cloudwatch_event_rule(app_name=app, account=env, region=region)
  
      for rule in event_rules:
          cloudwatch_client.remove_targets(Rule=rule, Ids=[app])
  
      return True